Type cleaning method



. June 18, 1957 E. G. BROWN 2,796,367

' TYPE CLEANING METHOD Filed Feb. 17, 1955 Q 4' .il: 1%- 1 2 1 o o ooo ooo o o o /dbooQo A oooooooooo'vo o oQga o \I/ 1 /2 'TiE: E

/o V INVENTOR.

U6N a BRODY Unite This invention relates to a method of and article for cleaning the ink from type characters on printing machines such as printers in electronic computing machines, or typewriting machines.

With the development of more complex calculating machines, computers, and the like, which include automatic printing machines or typewriters whose type is relatively inaccessible without partial disassembly of the machine, a corresponding need has arisen for a simple and rapid method or device for cleaning from such type characters the ink fouling the type characters. As is well known, when the type characters of a conventional typewriter become fouled with ink, the operator simply opens the cover of the machine and with a cloth or other type cleaner, rubs the ink off the type characters. In many of the present-day computers or calculators or other more complex machines having automatic printing machines or typewriters, the cleaning of the type characters is not as simple as the method above mentioned. With these latter machines the type characters are frequently relatively inaccessible and to clean the characters by the conventional methods requires a partial disassembly of the machine.

An object of my invention is the provision of a method for cleaning type on automatic printing machines or typewriting machines by inserting a type cleaning sheet between the type and the platen of the machine, after the fashion that a conventional piece of paper is inserted in the machine, with the cleaning sheet having a coating on that side facing the type, with such coating comprising an ink adhesive material, such that upon operating the machine in the conventional manner but with the inking device inoperative, the ink on the type characters will adhere to the material as the type characters strike the material, and when the type characters are removed from contact with the material the ink will be left on the cleaning sheet. With the cleaning sheet in place between the platen and the type characters, the machine is operated in the usual manner but with successively different type characters striking the same portions or the same positions on the ink adhesive material of the cleaning sheet to knead the material and work the ink therethrough and force the material against the type faces and against the exposed surface at the base of the raised type faces, and after the type characters have struck the cleaning sheet one or more times over the same portions of the material, the sheet is shifted to expose a fresh portion of the material to the type characters and the operation is repeated. Following the cleaning of all the type characters or the ink saturation of the cleaning material, the sheet is re moved from the machine.

Another object of the invention is the provision of a laminated type cleaning sheet for use in cleaning type characters according to the method above outlined, which sheet includes a backing sheet of relatively tough paper or other flexible material coated on one side with a layer of type cleaning material such as, for example, the commercial 'type cleaner readily available from Eberhard States Patent" ICC Faber Company of Brooklyn, New York, and sold under the name Star Plastic Type Cleaner.

Still another object of the invention is the provision of methods for applying a type cleaner to a backing sheet so that a uniform thickness, consistency, and adhesive qualities of the cleaner both for the paper and for the ink on type characters, may be readily obtained.

Still another object of the invention is the provision of a type cleaning sheet comprising a relatively tough, durable but flexible backing sheet coated on one surface with a putty-like material having an affinity for typing ink whereby, upon insertion of the cleaning sheet in a typewriting machine, and the impressing of the type characters against the coated side of the cleaning sheet, the ink on the type characters will adhere to the cleaning material and be thereby removed from the type characters.

Other objects, advantages, and meritorious features will more fully appear from the specification, claim, and accompanying drawing, wherein:

Fig. 1 is a top view of a type cleaning sheet embodying my invention; and

Fig. 2 is a cross sectional view through a portion of the sheet shown in Fig. 1 taken on the line 2-2.

In carrying out the objects of my invention, I have shown in Fig. 1 an illustrative embodiment of my type cleaning sheet. The sheet shown is particularly adapted for use with the International Business Machine printer, Model 402. It is to be understood, however, that sheets having different shapes are contemplated by my invention and I do not wish to limit myself to the embodiment shown in Fig. 1 except as defined in the appended claim. The sheet shown in Fig. 1 includes a backing layer or backing sheet 10 comprising a relatively durable, tough, strong, flexible paper. The sheet must be capable of withstanding repeated blows of the type characters against the cleaning sheet without fracturing. I have found that commercially available water color paper having a long fiber is very satisfactory. Backing sheets of other materials may also be satisfactory, such as sheets of woven cellulose fibers or plastic strands such as nylon strands.

Along the opposite side edges of the backing sheet it may be provided with apertures 12 which serve to hook the cleaning sheet to the paper carrying parts of the typewriting machine. While such holes 12 are shown, it is to be understood that with type cleaning sheets adapted for use in other makes and models of printers or typewriting machines, the holes might be unnecessary, and therefore omitted, or in cleaning sheets for use with still other machines, they might be of a different shape or position in the backing sheet.

Partially covering one side of the backing sheet 10 is a layer of type cleaning material indicated at 14 of a thickness approximating .04 of an inch. The marginal edges of the cleaning material are spaced from the edges of the backing sheet as shown, to provide a margin about the cleaning material through which the apertures 12 may extend. The margins of the backing sheet about the cleaning material 14- also serve to strengthen the cleaning sheet in and about the edges of the cleaning material.

The cleaning material 14 may be of different compositions. One cleaning material I have found to be particularly satisfactory is a product made by Eberhard Faber Company of Brooklyn, New York, and sold under the trade name Star Plastic Type Cleaner. This Star Plastic Type Cleaner is made according to 'a secret formula by a secret process but is readily available in bulk form upon application to the above named company. Such material, when purchased, is of a putty-like consistency and may be readily kneaded between the fingers. Its application to the backing sheet, and function in cleaning the type characters, will be hereinafter described.

Another cleaning material which I. have found to be Patented June 18, 1957v satisfactory is composed of equal parts of natural rubber and factice which are thoroughly masticated together as by passing them repeatedly between rollers. The factice may be either the natural variety or the synthetic variety which is termed Neofax. To this masticated mass of rubber and factice is added an equal quantity of an inert filler such as powdered mica or soapstone (steatite). The mica or soapstone serves as a filler and adds body to the material. To this mixture is then added oil selected from the two classes of oils comprising (1') fixed (fatty) oils derived from animal, vegetable, and marine sources, and consisting chiefly of glycerides and esters of fatty acids, or (2) mineral oils, derived from petroleum, coal, shale, etc., and consisting of hydrocarbons, with the amount of such oil that is added determining the consistency or viscosity of the finished product. If a greater amount of oil is added, such as With the addition of greater amounts of linseed oil to putty, the resulting product is less viscous and more tacky, while if a lesser amount of oil is added, the product is more viscous and less tacky. I have found that for most uses the proper proportion of oil that should be added is such as will yield a product that will not stick to the fingers when kneaded by hand, and yet which is of such consistency that it may be readily kneaded, similar to glazing putty. I have found that the proportion of 1 part oil to 100 parts of the mixture of the rubber, factice, :andfiller is satisfactory for most purposes.

The thinning of the cleaner with greater amounts of oil so that it is more tacky is desirable when fabricating cleaning sheets for use in certain makes or models of machines. Machines whose type characters strike the cleaning sheet With a very light force, or Whose type faces are of deeper relief than the average, require a softer cleaning material to ensure proper embedding of the type faces in. the cleaning layer. Proper embedding of the type faces in the cleaning layer requires that all of the raised portion and preferably the exposed surface at the base of the raised letter are pressed into the cleaning layer.

To this mixture of rubber, factice, filler, and oil may then be added. a coloring dye to give the cleaning material a pleasing appearance.

I have found four satisfactory methods of applying the cleaning material to the backing sheet. These methods apply both to the Star Plastic Type Cleaner as Well as to the cleaner whose composition is above described. According to the first method, the cleaning material is dissolved in toluene and while so dissolved is applied to one surface of the backing paper, either by spraying, painting, or calendaring, with the toluene then being evaporated out, leaving the resulting product in the same puttylike form as above described but in a coat or layer on the surface of the paper. Precautions should be taken to, ensure, by conventional spraying, painting, or calendering methods, a smooth layer of uniform thickness on the Pape Because the product is dissolved in toluene, the liquid mass. soaks into the paper slightly at one surface of the paper, and upon evaporation of the toluene the mass ad heres to the paper through its mechanical inter-engagement with the fibers of the paper. The same is true if, instead of using a paper backingsheet, a woven backing sheet of cellulose or plastic strandsv is used as above described. The inter-engagement of the cleaning material with the Woven strands of the backing sheet tends tocause adherence of the cleaning layer to the backing sheet.

According tothe second method of applying the clean ing material to the backing sheet, the putty-like mass is rolled between a pair of rollers into sheets. of a determined. thickness, with the sheets then being cut to size. One surface of each sheet is then coated with rubber cement, andsuch surfaceis then laid upon the backing sheet. Pressure, as by the platen of a press, is then applied to the layer of cleaning material to urge the same firmly against the backing sheet, to eliminate; air bubbles, and

urge the rubber cement into the backing sheet to form a good bond. While in the press, a low temperature heat may be applied to the cleaning sheet to set the rubber cement and firmly bond the cleaning material to the backing sheet.

According to the third, and preferred method, the putty-like mass is rolled out into sheets of a determined thickness. That surface of the sheets which is to lie against the backing sheet is then painted with a rubber solvent such as toluene. The toluene makes the surface of the cleaning layer tacky, and such surface is then placed against the backing sheet, and by means of a press, the cleaning layer is urged against the backing sheet, eliminating any air bubbles and urging the tacky surface of the layer to inter-engagement with the fibers of the backing sheet. While under pressure of the press, the toluene is evaporated from the cleaning sheet, as by the application of low temperature heat, and thereafter the cleaning sheet is removed from the press and is ready for use.

According to the fourth method of making the cleaning sheet, the putty-like mass is rolled directly onto the backing sheet by means of pressure rollers. The rollers serve to spread the mass in an even layer over the backing sheet. The pressure of the rollers down upon the cleaning material, urges the cleaning material against the backing sheet and forces the material into inter-engagement with the fibers of the backing sheet to adhere the material to the backing sheet. If, at the time the cleaning material is rolled into a layer upon the backing sheet, the material is heated, it will become tacky and a lesser amount of pressure by the rollers will be sufficient to adhere the cleaning material to the backing sheet. By varying the amount of heat and pressure applied to the cleaning material while rolling it on the backing sheet, the depth of penetration of the cleaning material into the backing sheet may be varied. As shown in Fig. 2, the cleaning material has penetrated as at 16 the surface of the backing sheet to lie below such surface in interengagement with the fibers. of the sheet.

In using the cleaning sheet to clean type characters of automatic printers or typewriting machines, the cleaning sheet is placed in the machine just as is an ordinary sheet of paper which is to be typed upon, with the cleaningmaterial facing the type characters so that when they are actuated they will strike the cleaning material. That surface of the backing sheet opposite the cleaning material is disposed adjacent the platen or other paper-supporting means of the machine which bears against a paper during printing or typing of the machine. The ink ribbon or other inking device of the machine is then disengaged so that the type characters Will strike the cleaning sheet without the interposition of the ink ribbon. Thereafter the machine is operated in the normal fashion r with each of the type characters being actuatedone or more times to strike the cleaning sheet. As is usual in the operation of the typewriting machine, the carriage supporting the paper being typed upon travels transversely during the typing, and such carriage will carry the cleaning sheet in like manner transversely through the machine. The platen may also be actuated in the usual manner to space between lines, and thereby carry the cleaning sheet to new positions so that the type characters will not repeat over that area of the cleaning material already impressed by the type.

As a type character strikes the cleaning material, the ink fouling the type character is attracted with a greater force to the cleaning material than to the face of the type, and therefore, when the type is removed from contact with the cleaning material, the ink remains with the cleaning material and is thereby removed from the type face. This afiinity of the ink for the cleaning material may, perhaps, be best explained as a molecular attraction of the ink, for the cleaning material. Typewriting machineink, asisfound. onink. ribbons or the like, is an oil base ink, i. e., the ink comprises an oil base in which is suspended a colored dye. This oil has a great affinity for the rubber of the cleaning material, and consequently when the rubber and oil of the ink are placed in contact, the ink adheres to or is drawn to the rubber. The attraction of the oil for the rubber greatly exceeds its attraction for the metal of which the type characters are made, and consequently the type characters are left clean when removed from contact with the cleaning material.

If the type characters are run over the same impressions left in the cleaning material layer by previous typing, in other words, if the machine is operated to type twice over the same area of the cleaning sheet, the second typing will tend to knead the cleaning material and there by cause the ink drawn off the type characters to be urged farther into the layer of cleaning material, instead of lying merely on the surface. This would occur if, for example, the letter 0 is struck and the type character 0 is impressed on the cleaning layer of the cleaning sheet. Thereafter, if the letter x is struck over the impression 011 the cleaning sheet left by the type character o, the cleaning material will be squeezed away to form the x impression, with a portion of such squeezed material being urged into the indentation of the o. In this way, the ink absorbed by the cleaning material is forced through the cleaning material so that it permeates the material and does not lie only at the surface of the cleaning layer.

As hereinabove mentioned, I have found that with the thickness of the cleaning material layer in the nature of .04 inch the layer will properly clean the type characters, and this will occur both by virtue of the pressing of the type faces or letters into the cleaning layer, and also by virtue of the upward squeezing or kneading of the puttylike layer as different type characters repeatedly strike the same positions on the cleaning sheet. As above mentioned in connection with the letters 0 and x, as the o strikes the sheet it forms an impression in the cleaning layer of ridges and indentations, and it is these ridges and indentations which rub against the letter x and the exposed surface at the base of the letter to attract the ink. These ridges and indentations in the cleaning layer are kneaded by the letter x to dififuse the ink into the cleaning layer.

I have mentioned above that the cleaning sheet herein disclosed is usable with the model 402 I. B. M. printer, and the nature of the cleaning operation of type characters by repetitiously striking the cleaning layer at the same position by different letters. When cleaning the I. B. M. printer, the machine is controlled to print repetitiously different letters, numeral-s, etc., on the same line, for example, twenty times on the same line and then the printer shifts the sheet to expose a fresh portion of the cleaning layer to the type. This repetitious printing on and periodic shifting of the cleaning sheet will effect a kneading of the entire cleaning layer and a cleaning of all the type.

In order to protect the cleaning layer 14 of the cleaning sheet prior to use, the layer may be covered with a sheet of cellophane or one of the common cellulose acetate derivatives.

What I claim is:

That method of cleaning the type characters of a printing machine comprising: inserting into the machine in the usual manner a backing sheet coated with a puttylike type-cleaning material, disposing the sheet such that the coated surface is in a position to be struck by the type characters of the machine during operation of the machine, rendering inoperative the inking device of the machine such that the type is not inked upon operation of the machine, operating the machine to cause different References Cited in the file of this patent UNITED STATES PATENTS 1,479,497 Cutler Jan. 1, 1924 1,735,480 flalaly et a1 Nov. 12, 1929 1,823,689 Kelley Sept. 15, 1931 2,394,855 Gould Feb. 12, 1946 2,494,047! Lay Jan. 10, 1950 FOREIGN PATENTS 9,622 Great Britain of 1896 817,345 France -5 May 24, 

